Re-lined pipe technique for wear mitigation in slurry transport pipeline

ABSTRACT

The present invention provides apparatus, including a pigging tool, that comprises a spraying mechanism configured to move along an inner surface of a pipeline, including a slurry transport pipeline in a minable oilsands facility or plant, and to spray a coating on the inner surface of the pipeline; and a curing source, including an ultraviolet (UV) light source, a microwave source or an RF source, configured to cure the coating sprayed on the inner surface of the pipeline in situ as the spray mechanism moves along the inner surface of the pipeline.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims benefit to provisional patent application Ser.No. 61/548,492, filed 18 Oct. 2011 (WFVA/CiDRA Nos. 712-2.362/CCS-0066),which is incorporated by reference in its entirety.

BACKGROUND OF THE INVENTION

1. Field of Invention

This invention relates to a technique for wear mitigation in a pipeline;and more particularly to a method and apparatus for re-lining a slurrytransport pipeline for wear mitigation.

2. Description of Related Art

To overcome the significant wear that can occur in pipelines carryingslurry materials, particularly as in the mineable oil sands industry,many producers are adopting ‘lined’ carbon steel pipes in the mostaggressive slurries, for example coarse tailings These steel pipes arelined with materials such as urethane with other elastomers. Forexample, one known lined pipe, such as Iracore International's Irathane®lined pipe, combines a thin layer of rubber against the inside wall ofthe pipe, for compliance, with a thicker layer of urethane-like material(Irathane®) over the rubber liner. While these materials provide goodresistance to abrasion, and have projected lifetimes of 10 years,ultrasonic non-destructive examination (NDE) approaches to detecting thelining wear (wall thickness) may be compromised, and in some cases arenot possible, due to the poor impedance discrimination between the steeland various liners (as compared to pipes having just steel).Consequently, monitoring the wear rates and status of a lined pipe isboth a challenge and a risk to the producer, as catastrophic failure canoccur, e.g., if the liner wears to the point of reaching the carbonsteel pipe, or if the liner is damaged and tears away from the outersteel pipe, exposing it directly to the abrasive slurry. This type offailure can result in loss of containment which could have environmentaland safety implications as well as introducing high opportunity costsdue to lost production

In view of this, there is a need in the industry to provide a techniquefor re-lining a pipeline, e.g., including a technique that does notpreclude ultrasonic non-destructive examination (NDE) approaches fordetecting the lining wear (wall thickness) to be implemented after thepipeline is re-lined as part of a routine maintenance schedule, which isa problem with liners known and used in the prior art.

SUMMARY OF THE INVENTION

In summary, the present invention provides a technique in which the wearin a pipe or pipeline is mitigated by the use of a so-called“sacrificial” coating re-applied each time the pipeline undergoes ascheduled maintenance shutdown. For example, during such a shut-down thepipe or pipeline may be cleaned using known ‘pigging’ technology, andthen a subsequent pigging tool may be introduced to the pipeline whichallows for the spray-coat application of a coating, such as a polymercoating, which is then cured (polymerized) in-situ. The coating isconfigured to have a high degree of abrasion-resistance, and thus thisdetermines potential coatings that may be applied. Some polymers may beused and designed to take on the electro-mechanical qualities of‘bridging groups’ incorporated into the monomer structure. As anexample, polymers can be made to be electrically conducting, ormagnetic, or have particular chemical affinities etc., or somecombination thereof The mechanical properties and hardness of thepolymer that may be used can also be controlled, enabling coatings thatexhibit a high abrasion and wear resistance.

In particular, the apparatus according to some embodiments of thepresent invention, may include, or take the form of, a sprayingmechanism in combination with a curing source, e.g., including anultraviolet (UV) light source, an microwave source, or an RF source. Thespraying mechanism may be configured to move along an inner surface of apipeline, including a slurry transport pipeline in a minable oilsandsfacility or plant, and to spray a coating on the inner surface of thepipeline. The curing source may be configured to cure the coatingsprayed on the inner surface of the pipeline in situ as the spraymechanism moves along the inner surface of the pipeline.

The apparatus according to the present invention may include one or moreof the following features:

The apparatus may be configured as, or forms part of, a pipe piggingtool.

The coating may be a monomer coating, which is understood to be achemical compound that can undergo polymerization, e.g., by exposing itto a UV light source.

The coating may be a polymer coating that is polymerized, e.g., by theUV light source, where a polymer is understood to be a chemical compoundor mixture of compounds formed by polymerization and consistingessentially of repeating structural units. The polymer coating may bedesigned to take on electro-mechanical qualities of ‘bridging groups’incorporated into a monomer structure. The polymer coating may beconfigured to have one or more characteristics or properties, includingbeing electrically conducting, or magnetic, or having particularchemical affinities, or some combination thereof.

The coating may have a high degree of abrasion and wear resistance.

The coating may be configured and sprayed on the inner surface of thepipeline so as to form an impedance discrimination between the pipelineand the coating, e.g., that does not preclude ultrasonic non-destructiveexamination (NDE) approaches for detecting lining wear or wallthickness, which was a problem with liner known and used in the priorart.

The apparatus may also include a signal processor configured to providesignalling to

-   -   move the spraying mechanism along the inner surface of the        pipeline and spray the coating on the inner surface of the        pipeline; and    -   cure with the curing source (e.g., including the ultraviolet        (UV) light source, the microwave source or the RF source) the        coating sprayed on the inner surface of the pipeline in situ as        the spray mechanism moves along the inner surface of the        pipeline.

The signal processor may be incorporated in the apparatus, such as thepigging tool. Alternatively, the signal processor may form part of aremotely operated controller, and the signalling may include, or takesthe form of, wireless signaling provided to the pigging tool.

The Method

Further, the present invention may also take the form of a methodcomprising steps of moving the spraying mechanism along the innersurface of the pipeline, including the slurry transport pipeline in theminable oilsands facility or plant, and spraying the coating on theinner surface of the pipeline; and curing with the curing source (e.g.,including the ultraviolet (UV) light source, the microwave source or theRF source) the coating sprayed on the inner surface of the pipeline insitu as the spray mechanism moves along the inner surface of thepipeline.

The method according to the present invention may include one or more ofthe following features:

The method may include initially cleaning the inner surface of pipeline,including using ‘pigging’ technology.

The method may include spraying a monomer coating, then polymerizing themonomer coating, e.g., via the UV irradiation.

The method may include using the technique, e.g., on a pipeline that mayform part of oilsands processing technology.

The method may be performed as part of a scheduled maintenance program,including during a shut-down, where the pipeline is cleaned using the‘pigging’ technology, and then a subsequent pigging tool may beintroduced to the pipeline which allows for a spray-coat application ofthe coating, such as a polymer coating, which is then cured in-situ.

The Signal Processor

Furthermore, the apparatus according to some embodiments of the presentinvention, may include, or take the form of, the signal processor thatis configured to provide the signalling to move the spraying mechanismalong the inner surface of the pipeline, including the slurry transportpipeline in the minable oilsands facility or plant, and spray thecoating on the inner surface of the pipeline; and cure with the curingsource (e.g., including the ultraviolet (UV) light source, the microwavesource or the RF source) the coating sprayed on the inner surface of thepipeline in situ as the spray mechanism moves along the inner surface ofthe pipeline.

BRIEF DESCRIPTION OF THE DRAWING

The drawing includes FIGS. 1-2, which are not necessarily drawn toscale, as follows:

FIG. 1 shows apparatus for re-lining a pipeline, according to someembodiments of the present invention.

FIG. 2 shows a signal processor for implementing the apparatus shown inFIG. 1, according to some embodiments of the present invention.

DETAILED DESCRIPTION OF BEST MODE OF THE INVENTION FIG. 1

In the technique according to the present invention, a so-called“sacrificial” coating may be applied to normal high wear pipes, e.g.,such as mild steel (carbon steel) pipes, to provide an “abrasionbarrier.” This coating may be applied using a pipe “pigging tool” thattraverses the pipeline and applies the coating compound and polymerizesthe coating as it passes down the pipe. FIG. 1 shows the concept andprinciple of operation of the technique, according to some embodimentsof the present invention. The pipeline, used for example in coarsetailings transport, may be cleaned using an initial pass by a piggingtool, then a tool designed to spray-coat the inner surface of the pipewith the monomer coating, then polymerize the coating via a UVirradiation, according to the present invention. The subsequent coating,while possibly even being thin, is designed to have sufficient wearresistance to allow the pipeline to be operated, e.g., for at least 6months, and/or to the next scheduled shutdown, without the slurrywearing through the coating and thus wearing directly the steel pipe.

In particular, FIG. 1 shows the apparatus generally indicated as 10which includes a spraying mechanism 12 in combination with a lightsource 14, including an ultraviolet (UV) light source. The apparatus 10may be configured as, or forms part of, a pipe pigging tool, althoughthe scope of the invention is not intended to be limited to anyparticular implementation in any particular tool either now known orlater developed in the future. The spraying mechanism 12 may beconfigured to move along an inner surface 16 of a pipeline 18, e.g.,including a slurry transport pipeline in a minable oilsands facility orplant (not shown), and spray a coating 20 (indicated as dashed lines inFIG. 1) on the inner surface 16 of the pipeline 18. The light source 14may be configured to cure the coating 20 sprayed on the inner surface 16of the pipeline 18 in situ as the spray mechanism 12 moves along theinner surface 16 of the pipeline 18. Light sources, including UV lightsources, are known in the art, and the scope of the invention is notintended to be limited to any particular type or kind thereof either nowknown or later developed in the future. The scope of the invention isnot intended to be limited to curing the coating 20 using a UV lightsource like element 14. For example, other types or kinds of curingsources may be used that are now known or later developed in the future,including a microwave source or an RF source.

The coating 16 may be a monomer coating, which can undergopolymerization, e.g., by exposing it to a UV light source. Monomer areknown in the art, and the scope of the invention is intended to belimited to any particular type or kind thereof either now known or laterdeveloped in the future. The coating 16 may be configured or designed totake on electro-mechanical qualities of ‘bridging groups’ incorporatedinto a monomer structure.

The coating 16 may be configured to have a high degree of abrasion andwear resistance, based at least partly on a particular application in aparticular pipeline, and/or on a particular scheduling associated with aparticular maintenance program. The scope of the invention is notintended to be limited to any particular degree of abrasion resistanceof the applied coating.

The coating 16 may be configured and sprayed on the inner surface 16 ofthe pipeline 18 so as to form an impedance discrimination and/orcharacteristic between the pipeline 18 and the coating 16, e.g., thatdoes not preclude ultrasonic non-destructive examination (NDE)approaches for detecting lining wear or wall thickness, including usingthe NDE technique set forth below. The whole thrust of the presentinvention is to provide a technique that allows the liner to be replacedbased on a liner maintenance cycle—6 to 12 months. One benefit of thetechnique according to the present invention is that NDE approaches maystill be used. It is also noteworthy that NDE/Haol can be used to ensurethe steel pipe is not being eroded, according to some embodiments of thepresent invention.

By way of example, in the oil sands industry pipe maintenance schedulingmay be regularly scheduled on approximately 6 month cycles. During themaintenance of a given pipeline, which may involve for example rotationof sections of the pipe to mitigate pipe wear, flow may be diverted to a‘swing’, or parallel line which during normal operations may begenerally inactive. Consequently, approximately at each 6 months, orscheduling period, the flow may be alternated between the producer lineand the ‘swing’ line, allowing the producer line to be ‘refurbished’with this applied coating, according to the present invention.

The approach according to the present invention has the advantage overother techniques for coatings in that the steel pipe is retained as aprimary flow pipe, and thus the mechanical integrity is maintained. NDEsensors designed to measure the pipe-wall thickness, e.g., such as knowntechniques and monitoring devices provided in the marketplace inconjunction, e.g. with the trademark HALO® system by the assignee of theinstant patent application, can be used to monitor the performance ofthe so-called “sacrificial” coating and ensure that the steel wall isnot being abraded significantly. By way of example, see the NDEtechniques disclosed in PCT application No. PCT/US11/28957, filed 18Mar. 2011, entitled “Method and Apparatus for Monitoring of ComponentsHousing Wall Thickness and Wear Monitoring,” that claims benefit toprovisional patent application No. 61/315,233, filed 18 Mar. 2010, whichare both incorporated herein by reference in their entirety. See alsothe corresponding U.S. national stage patent application Ser. No.13/635,449, filed 17 Sep. 2012, which is also incorporated herein byreference in its entirety. For the purpose of understanding the presentinvention, the scope thereof is intended to include other types or kindsof NDE either now known or later developed in the future. It is believedthat a combination of the so-called “sacrificial” coating, periodicrotation and monitoring may improve the carbon steel pipeline lifetimeby 3 to 5 fold compared to the use of known standard uncoated steelpipes known in the art. In addition, since the wall thickness of thecoated pipe can be measured, the risk of uncertainty to the operator maybe substantially mitigated, reduced and controlled.

FIG. 2: The Signal Processor

FIG. 2 shows, by way of example, apparatus generally indicated as 30according to some embodiments of the present invention in the form of asignal processor 30 a that may be configured to provide the signallingto move the spraying mechanism 12 along the inner surface 16 of thepipeline 18, including a slurry transport pipeline in the minableoilsands facility or plant (not shown), and spray the coating 20 on theinner surface 16 of the pipeline 18; and cure with the light source 14(including the ultraviolet (UV) light source, the microwave source orthe RF source) the coating 20 sprayed on the inner surface 16 of thepipeline 18 in situ as the spray mechanism 12 moves along the innersurface 16 of the pipeline 18.

By way of example, and consistent with that described herein, thefunctionality of the signal processor 30 a may be implemented usinghardware, software, firmware, or a combination thereof, although thescope of the invention is not intended to be limited to any particularembodiment thereof. In a typical software implementation, the signalprocessor 30 a would be one or more microprocessor-based architectureshaving a microprocessor, a random access memory (RAM), a read onlymemory (ROM), input/output devices and control, data and address busesconnecting the same. A person skilled in the art would be able toprogram such a microprocessor-based implementation to perform thefunctionality described herein without undue experimentation. The scopeof the invention is not intended to be limited to any particularimplementation using technology now known or later developed in thefuture. Moreover, the scope of the invention is intended to include thesignal processor 20 being a stand alone module, as shown, or in thecombination with other circuitry for implementing another module.Moreover, the real-time part may be implemented in hardware, while nonreal-time part may be done in software.

The apparatus 30 is also understood to include one or more other modules30 b for implementing the signal processing functionality, including oneor more memory modules, busing architecture, and/or input/outputmodules.

The Scope of the Invention

While the invention has been described with reference to an exemplaryembodiment, it will be understood by those skilled in the art thatvarious changes may be made and equivalents may be substituted forelements thereof without departing from the scope of the invention. Inaddition, may modifications may be made to adapt a particular situationor material to the teachings of the invention without departing from theessential scope thereof. Therefore, it is intended that the inventionnot be limited to the particular embodiment(s) disclosed herein as thebest mode contemplated for carrying out this invention.

What is claimed is:
 1. Apparatus comprising: a spraying mechanismconfigured to move along an inner surface of a pipeline, including aslurry transport pipeline in a minable oilsands facility or plant, andspray a coating on the inner surface of the pipeline; and a curingsource, including an ultraviolet (UV) light source, a microwave sourceor an RF source, configured to cure the coating sprayed on the innersurface of the pipeline in situ as the spray mechanism moves along theinner surface of the pipeline.
 2. Apparatus according to claim 1,wherein the apparatus is configured as, or forms part of, a pipe piggingtool.
 3. Apparatus according to claim 1, wherein the coating is amonomer coating that is polymerized by the curing source.
 4. Apparatusaccording to claim 1, wherein the coating is a polymer coating that ispolymerized by the curing source.
 5. Apparatus according to claim 4,wherein the polymer coating is designed to take on electro-mechanicalqualities of ‘bridging groups’ incorporated into a monomer structure. 6.Apparatus according to claim 4, wherein the polymer coating isconfigured to have particular chemical affinities.
 7. Apparatusaccording to claim 1, wherein the coating has a high degree of abrasionand wear resistance.
 8. Apparatus according to claim 1, wherein thecoating is configured and sprayed on the inner surface of the pipelineso as to form an impedance discrimination between the pipeline and thecoating that does not preclude ultrasonic non-destructive examination(NDE) approaches for detecting lining wear or wall thickness. 9.Apparatus according to claim 1, wherein the apparatus further comprises:a signal processor configured to provide signalling to move the sprayingmechanism along the inner surface of the pipeline and spray the coatingon the inner surface of the pipeline; and cure with the curing sourcethe coating sprayed on the inner surface of the pipeline in situ as thespray mechanism moves along the inner surface of the pipeline. 10.Apparatus according to claim 1, wherein the signalling is, or takes theform of, wireless signaling, including being provided from a remotelyoperated controller.
 11. A method comprising: moving a sprayingmechanism along an inner surface of a pipeline, including a slurrytransport pipeline in a minable oilsands facility or plant, and sprayinga coating on the inner surface of the pipeline; and curing with a curingsource, including an ultraviolet (UV) light source, a microwave sourceor an RF source, the coating sprayed on the inner surface of thepipeline in situ as the spray mechanism moves along the inner surface ofthe pipeline.
 12. A method according to claim 11, wherein the methodcomprises initially cleaning the inner surface of the pipeline,including cleaning the inner surface of the pipeline using ‘pigging’technology.
 13. A method according to claim 11, wherein the methodcomprises spraying a monomer coating, then polymerizing the coating viathe UV irradiation.
 14. A method according to claim 11, wherein thepipeline forms part of oilsands processing technology.
 15. A methodaccording to claim 11, wherein the method is performed as part of ascheduled maintenance program, including during a shut-down, where thepipeline is cleaned using ‘pigging’ technology, and then a subsequentpigging tool is introduced to the pipeline which allows for a spray-coatapplication of the coating, such as a polymer coating, which is thencured in-situ.
 16. Apparatus comprising: a signal processor configuredto provide signalling to move a spraying mechanism along an innersurface of a pipeline, including a slurry transport pipeline in aminable oilsands facility or plant, and spray a coating on the innersurface of the pipeline; and cure with a curing source, including anultraviolet (UV) light source, a microwave source or an RF source, thecoating sprayed on the inner surface of the pipeline in situ as thespray mechanism moves along the inner surface of the pipeline.